Flexible pressure vessel, apparatus and method for making same

ABSTRACT

A flexible pressure vessel is constructed from at least one pair of upper and mating lower dome shaped cell portions. The dome portions are molded from sheets of resilient material and joined together by radio frequency welding or high-strength adhesives. Upper and lower passageway portions extend outwardly from each cell portion to the surrounding sheet material. When the cell portions are joined the passageway portions are joined to form a passageway for connection to a valve or another cell. Upper and lower rings surround the upper and lower cell portions to provide reinforcement for the cells. First and second blankets of heavy-duty fiber reinforced material are attached over the upper and lower cell portions and stitched in place with heavy-duty stitching extending through the resilient material surrounding the cell portions. Cell shaped sponges impregnated with absorbent materials are encased in liquid and gas impermeable plastic tubing and inserted into the cells prior to joining of the cell portions. Heat-reflecting plastic film or metal foil is inserted between blankets and the cell portions. The heavy duty stitching is high-pressure loop and lock braiding. The passageway has a cross-section of between 0.050 and 0.100 inches. An apparatus and method are described for constructing the flexible pressure vessel.

FIELD OF INVENTION

The invention pertains to devices for storing gases and fluids underpressure. More particularly, the invention relates to pressure vesselsthat are formed out of flexible materials and that can be made toconform to a variety of shapes.

BACKGROUND OF THE INVENTION

Typically, pressure vessels capable of containing liquids or gases atsignificant pressures have involved fixed shape cylinders or spheresformed of high-strength metals such as steel or aluminum. Such pressurevessels, while successful for their designed applications, involve anumber of problems. First, such metallic cylinders are relatively heavycompared to the gases fluids that they contain. Second, pressurecylinders contain all of the gas or liquid in a single space. Should thevessel rupture, the entire vessel is destroyed, often with a violentexplosion sending shards of metal in all directions. Third, metalliccylinders have a definite shape and cannot be adapted to fit readily inmany space-constrained applications. The present invention involves anumber of small cells linked to each other by small conduits. The cellsare collected in a flexible matting material that adds to the structuralintegrity of the cells. A pressure vessel of this type can belightweight, adaptable to a variety of spaces and unusual applications,and is inherently safer in rupture situations.

Various designs have been developed using linked cell technologies, mostin the area of packaging materials. U.S. Pat. No. 4,551,379 issued toKerr discloses heat-sealable packaging material comprised ofinterconnected cells formed by laminating two facing sheets of airimpermeable material to define designated partitions and passageways.Discontinuities are provided at selected locations in each of thepartitions to provide limited communication between the adjacentpassages. The packaging material may be cut to the desired length andsealed at one end and then inflated by the insertion of a suitablemanifold at the other end and supplying pressurized air. While inflationis maintained, the passages are sealed by a heat-sealing bar trappingthe air within the passages.

U.S. Pat. No. 4,096,306 issued to Larson, describes air inflatedcushioning material comprising a series of interconnected cells formedby heat-sealing two facing sheets of film together. Here the cells areconnected to each other and a central passageway that is used to inflatethe cells. After inflation, the entrance to the passageway is thensealed.

U.S. Pat. No. 4,465,188, issued to Soroka et al., is directed to aninflatable packaging structure that includes an envelope with an innerliner. The inner liner located within envelope includes an inflatablefirst layer and a second or upper inflatable layer formed of flexiblesheets of heat sealable plastic material. The sheets are sealed to formzones that are connected to a single valve used for inflation.

U.S. Pat. No. 5,267,646 issued to Inoue et al. describes containersformed of laminated, interconnected cells. The cells are arranged inpairs that can communicate with each other. One chamber is designed tohold powdered, liquid or solid preparations while the second chamber isdesigned to hold an oxygen absorbent and a desiccant.

U.S. Pat. No. 5,824,392 issued to Gotoh et al., is directed to a methodand apparatus for producing an air cushion having a plurality ofindependent bubbles. The bubbles have communicating portions extendingin a continuous direction so that a plurality of them may be filledsimultaneously and then individually sealed. A sheet of bubbles isformed by heat-sealing films together having the bubble formingdepressions shapes with a hollow tubing communicating portion extendingat the center line of the films in a continuous direction. A portioncorresponding to the bubble forming depressions communicates with theright and left sides of the communicating portion. Air blown from anozzle and fed through the communicating portion inflates the bubbles sothat the films can be sealed at the communicating conjunction areamaking each bubble independent.

While other variations exist, the above-described designs involvinglinked cell technologies are typical of those encountered in the priorart. It is an objective of the present invention to provide a flexiblepressure vessel that is capable of maintaining gasses or liquids atrelatively high pressures. It is a further objective to provide thiscapability in a vessel that is light in weight and that presents asignificantly reduced risk of injury in rupture situations. It is astill further objective of the invention to provide a pressure vesselthat may be easily adapted to a variety of space constraints. It is yeta further objective to provide a pressure vessel that is durable, easilyserviced, and that may be produced inexpensively.

While some of the objectives of the present invention are disclosed inthe prior art, none of the inventions found include all of therequirements identified.

SUMMARY OF THE INVENTION

The present invention addresses many of the deficiencies of prior artflexible container and pressure vessel inventions and satisfies all ofthe objectives described above.

A flexible pressure vessel providing the desired features may beconstructed from the following components. At least one upperdome-shaped cell portion is provided. The upper cell portion is formedfrom a first sheet of resilient material and has an inner surface, anouter surface, an inner perimeter, an outer perimeter, a border of sheetmaterial surrounding the outer perimeter, and at least one upperpassageway portion. The upper passageway portion extends outwardly fromthe inner perimeter to the surrounding sheet material.

At least one mating lower dome-shaped cell portion is provided. Thelower cell portion is formed from a second sheet of resilient materialand has an inner surface, an outer surface, an inner perimeter, an outerperimeter, a border of sheet material surrounding the outer perimeter,and at least one lower passageway portion. The lower passageway portionextends outwardly from the inner perimeter to the surrounding sheetmaterial. The upper cell portion is joined to the mating lower cellportion such that a cell is formed. The cell has at least one passagewayextending outwardly from the cell for connection to either a passagewayof another cell or a valve.

A first ring is provided. The first ring has a first innercircumference, an outer circumference and a first predeterminedthickness. The first ring is sized and shaped to fit frictionally overthe upper cell portion and surround its outer perimeter. A second ringis provided. The second ring has a second inner circumference, an outercircumference and a second predetermined thickness. The ring second ringis sized and shaped to fit frictionally over the lower cell portion andsurround its outer perimeter.

A first flexible blanket is provided. The first blanket has an uppersurface, a lower surface and is sized and shaped to cover the upper cellportion and surrounding sheet material. The first blanket is fixedlyattached at its lower surface to the outer surface of the upper cellportion and surrounding sheet material. A second flexible blanket isprovided. The second blanket has an upper surface, a lower surface andis sized and shaped to cover the lower cell portion and surroundingsheet material. The second blanket is fixedly attached at its lowersurface to the outer surface of the lower cell portion and surroundingsheet material. A valve is provided. The valve is connected to thepassageway and provides means for controlling a flow of either of gassesand liquids into and out of the cell.

In a variant of the invention, heavy duty stitching is used to attachthe first blanket to the second blanket. The stitching penetrates thefirst and second blankets and the first and second resilient sheetsbetween the upper and lower cell portions and serves to prevent movementof the first and second rings with respect to the upper and lower cellportions.

In another variant, the heavy duty stitching is high-pressure hoop andlock braiding. In still another variant, a cell-shaped sponge isinserted between the upper cell portion and the lower cell portion priorto joining the upper and lower cell portions. The sponge serves toprevent the cell from collapsing after either of gas and liquid isremoved from the cell. In yet another variant, the sponge is impregnatedwith a with a zeolite compound.

In yet a further variant of the invention, either a heat-reflectingplastic film or a metal foil is inserted between at least one of thefirst blanket and the upper cell portion or the second blanket and thelower cell portion.

In still a further variant, the upper cell portion is joined to thelower cell portion by either radio frequency welding or high strengthadhesive. In another variant, either of the first and second blankets isformed of high-strength fiber impregnated material. In still anothervariant the passageway has a cross-section of between 0.050 and 0.100inches.

In yet a further variant, the flexible pressure vessel includes an upperretaining plate. The upper retaining plate has a third innercircumference, an outer circumference and a third pre-determinedthickness. The upper retaining plate is sized and shaped to fit over theupper cell portion and surround its outer perimeter when the upper cellportion is covered by the first blanket. The third inner circumferenceis larger than the outer circumference of the first ring.

A lower retaining plate is provided. The lower retaining plate has afourth inner circumference, an outer circumference and a fourthpre-determined thickness. The lower retaining plate is sized and shapedto fit over the lower cell portion and surround its outer perimeter whenthe lower cell portion is covered by the second blanket. The fourthinner circumference is larger than the outer circumference of the secondring. Means are provided for attaching the upper retaining plate to thelower retaining plate. When the upper retaining plate is attached to thelower retaining plate, surrounding the upper and lower cell portions andthe first and second blankets covering the first and second rings, thepressure capacity of the cell will be increased.

In still a further variant of the invention, the means for attaching theupper retaining plate to the lower retaining plate includes a series ofholes. The holes penetrate the upper retaining plate between its outercircumference and the third inner circumference, the lower retainingplate between its outer circumference and the fourth inner circumferenceand the first blanket, the border of sheet material surrounding theouter perimeter of the upper cell portion, the border of sheet materialsurrounding the outer perimeter of the lower cell portion and the secondblanket. The holes are outside of the outer circumference of the firstand second rings.

A series of fastening means are provided. The fastening means are sizedand shaped to pass through the series of holes and capable of securingthe upper retaining plate to the lower retaining plate. In anothervariant, the fastening means is a series of bolts and locking nuts. Instill another variant, the fastening means is a series of rivets.

In a further variant of the invention, the means for attaching the upperretaining plate to the lower retaining plate includes a series of holes.The holes penetrate the upper retaining plate between its outercircumference and the third inner circumference, the first blanket, theborder of sheet material surrounding the outer perimeter of the uppercell portion, the border of sheet material surrounding the outerperimeter of the lower cell portion and the second blanket. The holesare outside of the outer circumference of the first and second rings.

A series of pins is provided. The pins are affixed orthogonally along anupper surface of the lower retaining plate and are sized, shaped andlocated to fit slidably through the series of holes and extendingslightly above an upper surface of the upper retaining plate. A seriesof welds are used to fixedly attach the pins to the upper retainingplate, thereby securing the upper and lower retaining plates to eachother.

In still another variant, a series of cell shaped sponges is provided. Atube is provided. The tube is formed of flexible, gas and liquidimpervious material and is sized and shaped to surround the sponges. Thesponges are inserted in the tubing at spaced intervals. The encasedsponges are inserted between the upper cell portions and the lower cellportions prior to joining the upper and lower cell portions. The tubingextends through the passageways. The sponges serve to prevent the cellsfrom collapsing after either of gas and liquid is removed from thecells. The tube serves to prevent contamination of gas or liquid by theinner surfaces of the upper and lower cell portions.

In yet another, the sponges are impregnated with a zeolite compound.

In a final variant of the invention, the tube is formed from materialselected from the group comprising: thermoplastic polyurethaneelastomer, polyurethane polyvinyl chloride, polyvinyl chloride, andthermoplastic elastomer.

An apparatus for fabricating a flexible pressure vessel includes meansfor supporting first and second rolls of planar resilient material.First and second thermal die stamping stations are provided. Thestamping stations are capable of forming upper and lower cell portionswith attached passageway portions from said planar resilient material.Means are provided for moving the planar resilient material from thefirst and second rolls of planar resilient material into the first andsecond thermal die stamping stations.

A radio frequency welder is provided, the welder is capable of joiningthe upper cell portion to the lower cell portion to form cells withattached passageways. Means are provided for moving the upper and lowercell portions into the radio frequency welder. Means for fitting aseries of first and second rings frictionally over the upper and lowercell portions and to surrounding outer perimeters of the cell portions.

Means for supporting first and second rolls of high-strength fiberimpregnated blanket material are provided. Means are provided forattaching first and second portions of blankets material over the upperand lower cell portions. Means are provided for attaching a valve to thepassageway of a cell.

In variant of the apparatus for fabricating a flexible pressure vessel,means are provided for inserting a series of cell-shaped sponges betweenthe upper and lower cell portions. In still another variant, means forsupporting first and second rolls of either heat-reflecting plastic filmor metal foil are provided. Means are provided for attaching eitherheat-reflecting plastic film or metal foil to an outer surface of atleast one of the upper cell portion and the lower cell portion.

In another variant, means are provided for moving the blanket materialcovered cells portions to a high pressure hoop and lock braiding machinefor stitching. In yet another variant, a means are provided forinserting cell shaped sponges in a tube formed of flexible, gas andliquid impervious material and sized and shaped to surround saidsponges, at spaced intervals. Means are provided for inserting theencased sponges between the upper cell portions and the lower cellportions prior to joining the upper and lower cell portions. The tubeextends through the passageways.

In a final variant of the apparatus for fabricating a flexible pressurevessel means are provided for positioning an upper retaining plate tofit over the upper cell portion and surround an outer perimeter of saidupper cell portion when covered by the first portion of blanketmaterial. Means are provided for positioning a lower retaining plate tofit over the lower cell portion and surround an outer perimeter of saidlower cell portion when covered by the second portion of blanketmaterial.

Means are provided for producing a series of holes that penetrate theupper retaining plate between its outer circumference and a third innercircumference, the lower retaining plate between its outer circumferenceand a fourth inner circumference and the first portion of blanketmaterial, the border of sheet material surrounding an outer perimeter ofthe upper cell portion, a border of sheet material surrounding an outerperimeter of the lower cell portion and the second portion of blanketmaterial. The holes are outside of the outer circumference of the firstand second rings. Means are provided for inserting and securingfastening means through the holes, thereby securing the upper and lowerretaining plates to each other.

A method for fabricating a flexible pressure vessel includes thefollowing steps: Providing first and second rolls of planar resilientmaterial. Providing first and second thermal die stamping stations.Moving the first and second rolls of planar resilient material into thefirst and second thermal die stamping stations. Forming upper and lowercell portions with attached passageway portions from said planarresilient material in the first and second thermal die stampingstations.

Providing a radio frequency welder. Moving the first and second cellportions into the radio frequency welder. Joining the upper cell portionto the lower cell portion in the radio frequency welder to form cellswith attached passageways. Providing first and second rings. Fitting thefirst ring frictionally around an outer perimeter of the upper cellportion and fitting the second ring frictionally around an outerperimeter of the lower cell portion.

Providing first and second rolls of high-strength fiber impregnatedblanket material. Attaching first and second portions of blanketsmaterial over the upper and lower cell portions. Stitching through thefirst and second portions of blankets material and the resilientmaterial surrounding the upper and lower cell portions. Providing avalve and attaching the valve to the passageway of the cell.

A variant of the method for fabricating a flexible pressure vesselincludes the following additional steps: Providing a series ofcell-shaped sponges impregnated with a zeolite compound. Inserting thecell-shaped sponges between the upper and lower cell portions prior tojoining the upper and lower cell portions.

Another variant includes these steps: Providing first and second rollsof either heat-reflecting plastic film or metal foil. Attaching eitherheat-reflecting plastic film or metal foil to an outer surface of atleast one of the upper cell portion and the lower cell portion prior toattaching the first and second portions of blankets material over theupper and lower cell portions.

Still another variant includes moving the blanketed material coveredcell portions to a high pressure hoop and lock braiding machine prior tostitching through the first and second portions of blankets material andresilient material surrounding the upper and lower cell portions.

Yet a further variant of the method includes the following steps:Providing a series of cell shaped sponges. Providing a tube. The tube isformed of flexible, gas and liquid impervious material and is sized andshaped to surround the sponges. Providing means for inserting thesponges in the tube at spaced intervals. Providing means for insertingthe encased sponges between the upper cell portions and the lower cellportions prior to joining the upper and lower cell portions. Extendingthe tube through the passageways.

In a final variant of the invention, the method for fabricating aflexible pressure vessel includes the following additional steps:Providing upper and lower retaining plates. Providing a series of holes.The holes penetrate the upper retaining plate between its outercircumference and a third inner circumference, the lower retaining platebetween its outer circumference and a fourth inner circumference and thefirst portion of blanket material, a border of sheet materialsurrounding an outer perimeter of the upper cell portion, a border ofsheet material surrounding an outer perimeter of the lower cell portionand the second portion of blanket material. The holes are outside ofouter circumferences of the first and second rings respectively.Inserting and securing a series of fastening means through the holes,thereby securing the upper and lower retaining plates to each other.

In a final variant of the invention, the method for fabricating aflexible pressure vessel includes the following additional steps:Providing upper and lower retaining plates. Providing a series of holes.The holes penetrating the upper retaining plate between its outercircumference and the third inner circumference, the lower retainingplate between its outer circumference and the fourth inner circumferenceand the first blanket, the border of sheet material surrounding theouter perimeter of the upper cell portion, the border of sheet materialsurrounding the outer perimeter of the lower cell portion and the secondblanket. The holes are outside of the outer circumference of the firstand second rings. Inserting and securing a series of fastening meansthrough the holes, thereby securing the upper and lower retaining platesto each other.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a first embodiment of the inventionillustrating diamond-shaped cells, connecting passageways and a valve;

FIG. 2 is a plan view of a second embodiment of the inventionillustrating circular-shaped cells, connecting passageways and a valve;

FIG. 3 is a partial cross-sectional view of the FIG. 2 embodimentillustrating the upper and lower cell portions, upper and lower rings,upper and lower blankets and reinforcing stitching;

FIG. 4 is a partial cross-sectional view of the FIG. 2 embodimentillustrating the an included cell-shaped sponge;

FIG. 5 is a partial cross-sectional view of the FIG. 2 embodimentillustrating a metal or foil layer surrounding the cell portions;

FIG. 6 is a partial cross-sectional view of the FIG. 2 embodimentillustrating the radio frequency welding or high-strength adhesive usedto join the cell portions;

FIG. 7 is a partial cross-sectional view of the FIG. 2 embodimentillustrating first and second blankets formed of high-strength fiberimpregnated material;

FIG. 8 is a partial cross-sectional view of the FIG. 2 embodimentillustrating upper and lower retaining plates held in place by weldedpins;

FIG. 9 is a plan view of the FIG. 2 embodiment with the addition of theupper and lower retaining plates;

FIG. 10 is a partial plan view of the cells and connecting passageways;

FIG. 11 is a perspective view of a first ring;

FIG. 12 is a partial cross-sectional view of the FIG. 2 embodimentillustrating upper and lower retaining plates held in place by nuts andbolts;

FIG. 13 is an exploded perspective view of the upper and lower retainingplates and fastening bolts;

FIG. 14 is a schematic illustrating an apparatus for making the flexiblepressure vessel;

FIG. 15 is a plan view of the cell shaped sponges encased in animpermeable plastic tube;

FIG. 16 is a side elevational view of the cell-shaped sponges encased inan impermeable plastic tube; and

FIG. 17 is a partial cross-sectional view of the FIG. 2 embodimentillustrating the cell-shaped sponge encased in the impermeable plastictube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-3 illustrate a flexible pressure vessel 10 providing the desiredfeatures that may be constructed from the following components. At leastone upper dome-shaped cell portion 14 is provided. The upper cellportion 14 is formed from a first sheet 18 of resilient material and hasan inner surface 22, an outer surface 26, an inner perimeter 30, anouter perimeter 34, a border of sheet material 38 surrounding the outerperimeter 34, and at least one upper passageway portion 42. The upperpassageway portion 42 extends outwardly from the inner perimeter 30 tothe surrounding sheet material 38.

At least one mating lower dome-shaped cell portion 46 is provided. Thelower cell portion 46 is formed from a second sheet 50 of resilientmaterial and has an inner surface 54, an outer surface 58, an innerperimeter 62, an outer perimeter 66, a border of sheet material 70surrounding the outer perimeter 66, and at least one lower passagewayportion 74. The lower passageway portion 74 extends outwardly from theinner perimeter 62 to the surrounding sheet material 70. The upper cellportion 14 is joined to the mating lower cell portion 46 such that acell 78 is formed. The cell 78 has at least one passageway 82 extendingoutwardly from the cell 78 for connection to either a passageway 82 ofanother cell 78 or a valve 86.

A first ring 90 is provided. The first ring 90 has an innercircumference 94, an outer circumference 98 and a first predeterminedthickness 102. The first ring 90 is sized and shaped to fit frictionallyover the upper cell portion 14 and surround its outer perimeter 34. Asecond ring 106 is provided. The second ring 106 has an innercircumference 110, an outer circumference 114 and a second predeterminedthickness 118. The second ring 106 is sized and shaped to fitfrictionally over the lower cell portion 46 and surround its outerperimeter 66.

A first flexible blanket 122 is provided. The first blanket 122 has anupper surface 126, a lower surface 130 and is sized and shaped to coverthe upper cell portion 14 and surrounding sheet material 38. The firstblanket 122 is fixedly attached at its lower surface 130 to the outersurface 26 of the upper cell portion 14 and surrounding sheet material38. A second flexible blanket 134 is provided. The second blanket 134has an upper surface 138, a lower surface 142 and is sized and shaped tocover the lower cell portion 46 and surrounding sheet material 70. Thesecond blanket 134 is fixedly attached at its upper surface 138 to theouter surface 58 of the lower cell portion 46 and surrounding sheetmaterial 70. A valve 86 is provided. The valve 86 is connected to thepassageway 82 and provides means for controlling a flow of either ofgasses and liquids into and out of the cell 78.

In a variant of the invention, as illustrated in FIGS. 3 and 4, heavyduty stitching 146 is used to attach the first blanket 122 to the secondblanket 134. The stitching 146 penetrates the first 122 and second 134blankets and the first 18 and second 50 resilient sheets between theupper 14 and lower 46 cell portions and serves to prevent movement ofthe first 90 and second 106 rings with respect to the upper 14 and lower46 cell portions.

In another variant, as illustrated in FIG. 4, the heavy duty stitching146 is high-pressure hoop and lock braiding 150. In still anothervariant, also illustrated in FIG. 4, a cell-shaped sponge 154 isinserted between the upper cell portion 14 and the lower cell portion 46prior to joining the upper 14 and lower 46 cell portions. The sponge 154serves to prevent the cell 78 from collapsing after either of gas andliquid is removed from the cell 78. In yet another variant, the sponge154 is impregnated with a zeolite compound.

In yet a further variant of the invention, as illustrated in FIG. 5,either a heat-reflecting plastic film 158 or a metal foil 162 isinserted between at least one of the first blanket 122 and the uppercell portion 14 or the second blanket 134 and the lower cell portion 46.

In still a further variant, as illustrated in FIG. 6, the upper cellportion 14 is joined to the lower cell portion 46 by either radiofrequency welding 166 or high strength adhesive 170. In another variant,as illustrated in FIG. 7, either of the first 122 and second 134blankets is formed of high-strength fiber impregnated material 174. Instill another variant the passageway 82 has a cross-section of between0.050 and 0.100 inches.

In yet a further variant, as illustrated in FIGS. 8, 9, 12 and 13, theflexible pressure vessel 10 includes an upper retaining plate 250. Theupper retaining plate 250 has a third inner circumference 254, an outercircumference 258 and a third predetermined thickness 262. The upperretaining plate 250 is sized and shaped to fit over the upper cellportion 14 and surround its outer perimeter 34 when the upper cellportion 14 is covered by the first blanket 122. The third innercircumference 254 is larger than the outer circumference 98 of the firstring 90.

A lower retaining plate 266 is provided. The lower retaining plate 266has a fourth inner circumference 270, an outer circumference 274 and afourth pre-determined thickness 278. The lower retaining plate 266 issized and shaped to fit over the lower cell portion 46 and surround itsouter perimeter 66 when the lower cell portion 46 is covered by thesecond blanket 134. The fourth inner circumference 270 is larger thanthe outer circumference 114 of the second ring 106. Means 282 areprovided for attaching the upper retaining plate 250 to the lowerretaining plate 266. When the upper retaining plate 250 is attached tothe lower retaining plate 266, surrounding the upper 14 and lower 46cell portions and the first 122 and second 134 blankets covering thefirst 90 and second 106 rings, the pressure capacity of the cell 78 willbe increased.

In still a further variant of the invention, the means 282 for attachingthe upper retaining plate 250 to the lower retaining plate 266 includesa series of holes 286. The holes 286 penetrate the upper retaining plate250 between its outer circumference 258 and the third innercircumference 254, the lower retaining plate 266 between its outercircumference 278 and the fourth inner circumference 274 and the firstblanket 122, the border of sheet material 38 surrounding the outerperimeter 34 of the upper cell portion 14, the border of sheet material70 surrounding the outer perimeter 66 of the lower cell portion 46 andthe second blanket 134. The holes 286 are outside of the outercircumference 98, 114 of the first 90 and second 106 rings.

A series of fastening means 290 are provided. The fastening means 290are sized and shaped to pass through the series of holes 286 and capableof securing the upper retaining plate 250 to the lower retaining plate266. In another variant, as illustrated in FIGS. 12 and 13, thefastening means 290 is a series of bolts 294 and locking nuts 298. Instill another variant, the fastening means 290 is a series of rivets302. (Figure needed)

In a further variant of the invention, as illustrated in FIG. 8, themeans 282 for attaching the upper retaining plate 250 to the lowerretaining plate 266 includes a series of holes 286. The holes 286penetrate the upper retaining plate 250 between its outer circumference258 and the third inner circumference 254, the first blanket 122, theborder of sheet material 38 surrounding the outer perimeter 34 of theupper cell portion 14, the border of sheet material 70 surrounding theouter perimeter 66 of the lower cell portion 46 and the second blanket134. The holes 286 are outside of the outer circumference 98, 114 of thefirst 90 and second rings 106.

A series of pins 306 is provided. The pins 306 are affixed orthogonallyalong an upper surface 310 of the lower retaining plate 266 and aresized, shaped and located to fit slidably through the series of holes286 and extending slightly above an upper surface 314 of the upperretaining plate 250. A series of welds 318 are used to fixedly attachthe pins 306 to the upper retaining plate 250, thereby securing theupper 250 and lower 266 retaining plates to each other.

In still another variant, as illustrated in FIGS. 15-17, a series ofcell shaped sponges 154 is provided. A tube 338 is provided. The tube338 is formed of flexible, gas and liquid impervious material and issized and shaped to surround the sponges 154. The sponges 154 areinserted in the tube 154 at spaced intervals. The encased sponges 154are inserted between the upper cell portions 14 and the lower cellportions 46 prior to joining the upper 14 and lower 46 cell portions.The tube 338 extends through the passageways 82. The sponges 154 serveto prevent the cells 78 from collapsing after either of gas and liquidis removed from the cells 78. The tube 338 serves to preventcontamination of gas or liquid by the inner surfaces 22, 54 of the upper14 and lower 46 cell portions.

In yet another variant, the sponges 154 are impregnated with a zeolitecompound.

In a final variant of the invention, the tube 338 is formed frommaterial selected from the group comprising: thermoplastic polyurethaneelastomer, polyurethane polyvinyl chloride, polyvinyl chloride, andthermoplastic elastomer.

An apparatus 178 for fabricating a flexible pressure vessel 10 asillustrated in FIG. 14, includes means for supporting first 182 andsecond 186 rolls of planar resilient material 18, 50. First 190 andsecond 194 thermal die stamping stations are provided. The stampingstations 190, 194 are capable of forming the upper 14, and lower 46 cellportions with attached passageway portions 42 from said planar resilientmaterial 18, 50. Means 198 are provided for moving said planar resilientmaterial 18, 50 from the first 182 and second 186 rolls of planarresilient material 18, 50 into the first 190 and second 194 thermal diestamping stations.

A radio frequency welder 206 is provided, the welder 206 is capable ofjoining the upper cell portion 14 to the lower cell portion 46 to formcells with attached passageways 82. Means 210 are provided for movingthe upper 14 and lower 46 cell portions into the radio frequency welder206. Means for fitting series of first 90 and second 106 ringsfrictionally over the upper cell portion 14 and lower cell portion 46 tosurround outer perimeters 34, 66.

Means for supporting first 226 and second 230 rolls of high-strengthfiber impregnated blanket material 174 are provided. Means 234 areprovided for attaching first 122 and second 134 portions of blanketmaterial over the upper 14 and lower 46 cell portions. Means 246 areprovided for attaching a valve 86 to a passageway 82 of a cell 78.

In a variant of the apparatus 178 for fabricating a flexible pressurevessel 10, a series of cell-shaped sponges 154 are provided. Means 202are provided for inserting a series of cell-shaped sponges 154 betweenthe upper 14 and lower 46 cell portions prior to joining the upper 14and lower 46 cell portions.

In another variant, means for supporting first 214 and second 218 rollsof either heat-reflecting plastic film 158 or metal foil 162 areprovided. Means 222 are provided for attaching either heat-reflectingplastic film 158 or metal foil 162 to the outer surface 26, 58 of atleast one of the upper cell portion 14 and the lower cell portion 46. Instill another variant, means 238 are provided for moving the blanketedmaterial covered cells portions 78 to a high pressure hoop and lockbraiding machine 242 for stitching.

In yet another variant, as illustrated in FIGS. 14-17, means 342 areprovided for inserting cell shaped sponges 154 in a tube 338 formed offlexible, gas and liquid impervious material and sized and shaped tosurround said sponges 154, at spaced intervals. Means 346 are providedfor inserting the encased sponges 154 between the upper cell portions 14and the lower cell portions 46 prior to joining the upper 14 and lower46 cell portions. The tube 338 extends through the passageways 82.

In a final variant of the apparatus 178 for fabricating a flexiblepressure vessel 10 means 322 are provided for positioning an upperretaining plate 250 to fit over the upper cell portion 14 and surroundan outer perimeter 34 of said upper cell portion 14 when covered by thefirst portion of blanket material 122. Means 326 are provided forpositioning a lower retaining plate 266 to fit over the lower cellportion 46 and surround an outer perimeter 66 of said lower cell portion46 when is covered by the second portion of blanket material 134.

Means 330 are provided for producing a series of holes 286 thatpenetrate the upper retaining plate 250 between its outer circumference258 and a third inner circumference 254, the lower retaining plate 266between its outer circumference 278 and a fourth inner circumference 274and the first portion of blanket material 122, a border of sheetmaterial 38 surrounding an outer perimeter 34 of the upper cell portion14, a border of sheet material 70 surrounding an outer perimeter 66 ofthe lower cell portion 46 and the second portion of blanket material134. The holes 286 are outside of the outer circumference 98, 114 of thefirst 90 and second 106 rings. Means 334 are provided for inserting andsecuring fastening means 290 through the holes 286, thereby securing theupper 250 and lower 266 retaining plates to each other.

The flexible pressure vessel 10 and apparatus 178 and method for makingsame have been described with reference to particular embodiments. Othermodifications and enhancements can be made without departing from thespirit and scope of the claims that follow.

What is claimed is:
 1. A flexible pressure vessel, comprising: at leastone upper dome-shaped cell portion, said upper cell portion being formedfrom a first sheet of resilient material and having an inner surface, anouter surface, an inner perimeter, an outer perimeter, a border of sheetmaterial surrounding said outer perimeter, and at least one upperpassageway portion, said upper passageway portion extending outwardlyfrom said inner perimeter to said surrounding sheet material; at leastone mating lower dome-shaped cell portion, said lower cell portion beingformed from a second sheet of resilient material and having an innersurface, an outer surface, an inner perimeter, an outer perimeter, aborder of sheet material surrounding said outer perimeter, and at leastone lower passageway portion, said lower passageway portion extendingoutwardly from said inner perimeter to said surrounding sheet material;said upper cell portion being joined to said mating lower cell portionsuch that a cell is formed, said cell having at least one passagewayextending outwardly from said cell for connection to either of apassageway of another cell and a valve; a first ring, said first ringhaving a first inner circumference, an outer circumference and a firstpredetermined thickness; said first ring being sized and shaped to fitfrictionally over the upper cell portion and surround its outerperimeter; a second ring, said second ring having a second innercircumference, an outer circumference and a second predeterminedthickness; said second ring being sized and shaped to fit frictionallyover the lower cell portion and surround its outer perimeter; a firstflexible blanket, said first blanket having an upper surface, a lowersurface and being sized and shaped to cover said upper cell portion andsurrounding sheet material; said first blanket being fixedly attached atits lower surface to the outer surface of said upper cell portion andsurrounding sheet material; a second flexible blanket, said secondblanket having an upper surface, a lower surface and being sized andshaped to cover said lower cell portion and surrounding sheet material;said second blanket being fixedly attached at its upper surface to theouter surface of said lower cell portion and surrounding sheet material;and a valve, said valve being connected to said passageway and providingmeans for controlling a flow of either of gasses and liquids into andout of the cell.
 2. A flexible pressure vessel as described in claim 1,wherein heavy duty stitching is used to attach the first blanket to thesecond blanket, said stitching penetrating the first and second blanketsand the first and second resilient sheets between the upper and lowercell portions and serving to prevent movement of the first and secondrings with respect to the upper and lower cell portions.
 3. A flexiblepressure vessel as described in claim 2, wherein the heavy dutystitching is high pressure hoop and lock braiding.
 4. A flexiblepressure vessel as described in claim 1, wherein a cell-shaped sponge isinserted between the upper cell portion and the lower cell portion priorto joining said upper and lower cell portions, said sponge serving toprevent said cell from collapsing after either of gas and liquid isremoved from the cell.
 5. A flexible pressure vessel as described inclaim 4, wherein the sponge is impregnated with a zeolite compound.
 6. Aflexible pressure vessel as described in claim 1, wherein either of aheat-reflecting plastic film and a metal foil is inserted between atleast one of the first blanket and the upper cell portion and the secondblanket and the lower cell portion.
 7. A flexible pressure vessel asdescribed in claim 1, wherein the upper cell portion is joined to thelower cell portion by either of radio frequency welding and highstrength adhesive.
 8. A flexible pressure vessel as described in claim1, wherein either of the first and second blankets is formed ofhigh-strength fiber impregnated material.
 9. A flexible pressure vesselas described in claim 1, wherein the passageway has a cross-section ofbetween 0.050 and 0.100 inches.
 10. A flexible pressure vessel asdescribed in claim 1, further comprising: an upper retaining plate, saidupper retaining plate having a third inner circumference, an outercircumference and a third pre-determined thickness; said upper retainingplate being sized and shaped to fit over the upper cell portion andsurround its outer perimeter when said upper cell portion is covered bysaid first blanket; said third inner circumference being larger than theouter circumference of said first ring; a lower retaining plate, saidlower retaining plate having a fourth inner circumference, an outercircumference and a fourth pre-determined thickness; said lowerretaining plate being sized and shaped to fit over the lower cellportion and surround its outer perimeter when said lower cell portion iscovered by said second blanket; said fourth inner circumference beinglarger than the outer circumference of said second ring; means forattaching said upper retaining plate to said lower retaining plate; andwhereby, when the upper retaining plate is attached to the lowerretaining plate, surrounding the upper and lower cell portions and thefirst and second blankets covering the first and second rings, thepressure capacity of the cell will be increased.
 11. A flexible pressurevessel as described in claim 10, wherein the means for attaching theupper retaining plate to the lower retaining plate further comprises: aseries of holes, said holes penetrating said upper retaining platebetween its outer circumference and said third inner circumference, saidlower retaining plate between its outer circumference and said fourthinner circumference and said first blanket, the border of sheet materialsurrounding the outer perimeter of the upper cell portion, the border ofsheet material surrounding the outer perimeter of the lower cell portionand the second blanket; said holes being outside of the outercircumference of said first and second rings; a series of fasteningmeans, said fastening means being sized and shaped to pass through saidseries of holes and capable of securing said upper retaining plate tosaid lower retaining plate.
 12. A flexible pressure vessel as describedin claim 11, wherein the fastening means is a series of bolt and lockingnuts.
 13. A flexible pressure vessel as described in claim 11, whereinthe fastening means is a series of rivets.
 14. A flexible pressurevessel as described in claim 10, wherein the means for attaching theupper retaining plate to the lower retaining plate further comprises: aseries of holes, said holes penetrating said upper retaining platebetween its outer circumference and said third inner circumference, saidfirst blanket, the border of sheet material surrounding the outerperimeter of the upper cell portion, the border of sheet materialsurrounding the outer perimeter of the lower cell portion and the secondblanket; said holes being outside of the outer circumference of saidfirst and second rings; a series of pins, said pins being affixedorthogonally along an upper surface of said lower retaining plate andbeing sized, shaped and disposed to fit slidably through said series ofholes and extending slightly above an upper surface of said upperretaining plate; and a series of welds, said welds fixedly attachingsaid pins to said upper retaining plate, thereby securing said upper andlower retaining plates to each other.
 15. A flexible pressure vessel asdescribed in claim 1, further comprising: a series of cell shapedsponges; a tube, said tube being formed of flexible, gas and liquidimpervious material and being sized and shaped to surround said sponges;said sponges being inserted in said tube at spaced intervals, theencased sponges being inserted between the upper cell portions and thelower cell portions prior to joining said upper and lower cell portions,said tube extending through said passageways; said sponges serving toprevent said cells from collapsing after either of gas and liquid isremoved from the cells; and said tube serving to prevent contaminationof either of gas and liquid by the inner surfaces of the upper and lowercell portions.
 16. A flexible pressure vessel as described in claim 15,wherein the sponge is impregnated with a zeolite compound.
 17. Aflexible pressure vessel as described in claim 15, wherein the tube isformed from material selected from the group comprising: thermoplasticpolyurethane elastomer, polyurethane polyvinyl chloride, polyvinylchloride, thermoplastic elastomer.
 18. An apparatus for fabricating aflexible pressure vessel, comprising: means for supporting first andsecond rolls of planar resilient material; first and second thermal diestamping stations, said stamping stations being capable of forming upperand lower cell portions with attached passageway portions from saidplanar resilient material; means for moving said planar resilientmaterial from said first and second rolls of planar resilient materialinto said first and second thermal die stamping stations; a radiofrequency welder, said welder being capable of joining the upper cellportion to the lower cell portion to form cells with attachedpassageways; means for moving the upper and lower cell portions into theradio frequency welder; means for fitting a plurality of first andsecond rings frictionally over the upper and lower cell portions andsurrounding outer perimeters of said cell portions means for supportingfirst and second rolls of high-strength fiber impregnated blanketmaterial; means for attaching first and second portions of blanketsmaterial over the upper and lower cell portions; and means for attachinga valve to the passageway of a cell.
 19. An apparatus for fabricating aflexible pressure vessel, as described in claim 18, further comprising:means for inserting a series of cell-shaped sponges between the upperand lower cell portions prior to joining said upper and lower cellportions.
 20. An apparatus for fabricating a flexible pressure vessel,as described in claim 18, further comprising: means for supporting firstand second rolls of either of heat-reflecting plastic film and metalfoil; and means for attaching either of heat-reflecting plastic film andmetal foil to an outer surface of at least one of the upper cell portionand the lower cell portion.
 21. An apparatus for fabricating a flexiblepressure vessel, as described in claim 18, further comprising means formoving the blanketed material covered cells portions to a high-pressurehoop and lock braiding machine.
 22. An apparatus for fabricating aflexible pressure vessel, as described in claim 18, further comprising:means for inserting cell shaped sponges in a tube formed of flexible,gas and liquid impervious material and sized and shaped to surround saidsponges, at spaced intervals; and means for inserting said encasedsponges between the upper cell portions and the lower cell portionsprior to joining said upper and lower cell portions, said tube extendingthrough said passageways.
 23. An apparatus for fabricating a flexiblepressure vessel, as described in claim 18, further comprising: means forpositioning an upper retaining plate to fit over the upper cell portionand surround an outer perimeter of said upper cell portion when coveredby said first portion of blanket material; means for positioning a lowerretaining plate to fit over the lower cell portion and surround an outerperimeter of said lower cell portion when covered by said second portionof blanket material; means for producing a series of holes, said holespenetrating said upper retaining plate between its outer circumferenceand a third inner circumference, said lower retaining plate between itsouter circumference and a fourth inner circumference and said firstportion of blanket material, border of sheet material surrounding anouter perimeter of the upper cell portion, a border of sheet materialsurrounding an outer perimeter of the lower cell portion and said secondportion of blanket material; said holes being outside of the outercircumference of said first and second rings; and means for insertingand securing fastening means through said holes, thereby securing saidupper and lower retaining plates to each other.
 24. A method forfabricating a flexible pressure vessel, comprising: providing first andsecond rolls of planar resilient material; providing first and secondthermal die stamping stations; moving said first and second rolls ofplanar resilient material into said first and second thermal diestamping stations; forming upper and lower cell portions with attachedpassageway portions from said planar resilient material in said firstand second thermal die stamping stations; providing a radio frequencywelder; moving the first and second cell portions into the radiofrequency welder; joining the upper cell portion to the lower cellportion in the radio frequency welder to form cells with attachedpassageways; providing first and second rings; fitting said first ringfrictionally around an outer perimeter of the upper cell portion andfitting said second ring frictionally around an outer perimeter of thelower cell portion; providing first and second rolls of high-strengthfiber impregnated blanket material; attaching first and second portionsof blankets material over the upper and lower cell portions; stitchingthrough the first and second portions of blanket material and resilientmaterial surrounding the upper and lower cell portions; providing avalve; attaching said valve to said passageway of said cell.
 25. Amethod for fabricating a flexible pressure vessel as described in claim24, further comprising: providing a series of cell-shaped sponges; andinserting said cell-shaped sponges between the upper and lower cellportions prior to joining said upper and lower cell portions.
 26. Amethod for fabricating a flexible pressure vessel as described in claim24, further comprising: providing first and second rolls of either ofheat-reflecting plastic film and metal foil; and attaching either ofheat-reflecting plastic film and metal foil to an outer surface of atleast one of the upper cell portion and the lower cell portion prior toattaching the first and second portions of blankets material over theupper and lower cell portions.
 27. A method for fabricating a flexiblepressure vessel as described in claim 24, further comprising moving theblanketed material covered cells portions to a high pressure hoop andlock braiding machine prior to stitching through the first and secondportions of blankets material and resilient material surrounding theupper and lower cell portions.
 28. A method for fabricating a flexiblepressure vessel as described in claim 24, further comprising: providinga series of cell shaped sponges; providing a tube, said tube beingformed of flexible, gas and liquid impervious material and being sizedand shaped to surround said sponges; inserting said sponges in saidtubing at spaced intervals; inserting the encased sponges between theupper cell portions and the lower cell portions prior to joining saidupper and lower cell portions, said tubing extending through saidpassageways.
 29. A method for fabricating a flexible pressure vessel asdescribed in claim 24, further comprising: providing upper and lowerretaining plates; providing a series of holes, said holes penetratingsaid upper retaining plate between its outer circumference and a thirdinner circumference, said lower retaining plate between its outercircumference and a fourth inner circumference and said first portion ofblanket material a border of sheet material surrounding an outerperimeter of the upper cell portion, a border of sheet materialsurrounding an outer perimeter of the lower cell portion and the secondportion of blanket material; said holes being outside of outercircumferences of said first and second rings respectively; andinserting and securing a series of fastening means through said holes,thereby securing said upper and lower retaining plates to each other.